.menu

os.pullEvent = os.pullEventRaw

local w,h = term.getSize()

function printCentered (y,s)
    local x = math.floor((w - string.len(s)) / 2)
    term.setCursorPos(x , y)
    term.clearLine()
    term.write(s)
end

function printLeft (y,s)
    local x = math.floor((w - string.len(s)) / 2)
    term.setCursorPos(x - 18 , y)
    term.clearLine()
    term.write(s)
end

local nOption = 1

local function drawMenu()
    term.clear()
    term.setCursorPos(1,1)
    term.write("Atlantica OS v1.1")
end

term.clear()
local function drawFrontend()
        printCentered(math.floor(h/2) - 3, "")
    printCentered(math.floor(h/2) - 2, "Desktop")
        printCentered(math.floor(h/2) - 1, "")
    printCentered(math.floor(h/2) + 0, ((nOption == 1) and "[ Command ]") or "Command" )
        printCentered(math.floor(h/2) + 1, "")
    printCentered(math.floor(h/2) + 2, ((nOption == 2) and "[ Programs ]") or "Programs" )
        printCentered(math.floor(h/2) + 3, "")
    printCentered(math.floor(h/2) + 4, ((nOption == 3) and "[ Shutdown ]") or "Shutdown" )
end

drawMenu()
drawFrontend()

while true do
    local e,p = os.pullEvent()
        if e == "key" then
            local key = p
            if  key == 17 or key == 200 then

                if nOption > 1 then
                    nOption = nOption -1
                    drawMenu()
                    drawFrontend()
                    end
                elseif key == 31 or key == 208 then
                    if nOption < 3 then
                    nOption = nOption + 1
                    drawMenu()
                    drawFrontend()
                    end

            elseif key == 28 then
                break
                end
            end
        end
term.clear()

if nOption == 1 then
    shell.run(".command")
elseif nOption == 2 then
    shell.run(".programs")
else
    os.shutdown()
end